1. Field of the Invention
The present invention relates to a solid-state camera using a solid-state memory apparatus as a recording medium for a photographed image and the solid-state memory apparatus.
2. Related Background Art
An electronic still camera using a memory not requiring a movable mechanism for recording/reproduction of information (to be referred to as a solid-state camera hereinafter) has attracted attention as a successor of a silver chloride still camera and a video floppy electronic still camera. In an electronic still camera, instantaneous reproduction of a photographed image, image transfer, computer image processing, electronic image filing and the like can be easily performed by electronically processing image information. In the case of using a compact magnetic sheet called a video floppy as a recording medium, however, movable portions such as a rotating mechanism for the magnetic sheet and a head moving mechanism for positioning a magnetic head with the precision of several tens to hundreds of .mu.m in terms of a track pitch are required, thereby increasing the manufacturing cost of a camera and limiting use the environments in which it can be used and limiting its operation speed. These problems are similarly posed when an optical disk or optical magnetic disk is used as a recording medium.
The solid-state camera has been proposed as a camera capable of solving the above problems. FIG. 1 shows an arrangement of a solid-state camera system. Referring to FIG. 1, a memory cartridge 12 as a solid-state memory apparatus for storing image information can be detached from a camera main body 10 of the solid-state camera. A reproducing apparatus 14 reproduces stored information in the memory cartridge 12. The memory cartridge 12 comprises, e.g., an IC memory device, a memory controller, and a backup power source therefor. As the IC memory device, an SRAM, a DRAM, an EPROM, an EEPROM, or the like is used. The memory cartridge 12 and the camera main body 10 are connected by using, e.g., a metal connector, a transmit coil, or a photocoupler. An image photographed by the camera main body 10 is stored in a predetermined format by the memory cartridge 12. By connecting the memory cartridge 12 to the reproducing apparatus 14 to reproduce the stored image, electronic image data can be transmitted from the reproducing apparatus to a TV monitor, a printer, a transmitter, a filing apparatus, and the like.
In the conventional solid-state camera having the above arrangement, however, since the memory cartridge 12 can be detached from the camera main body 10, communication between the memory cartridge 12 and the camera main body 10 must be perfect upon photographing. In addition, the memory cartridge 12 itself requires no circuit defects, and a sufficient capacity for the backup power source, or the like to function. If a user operates a release button without noticing such defects, he or she cannot perform a photographing operation because an image to be photographed is not recorded.
Furthermore, the camera main body 10 must include a power source for driving various signal processors and exposure control means such as a lens driving means and an aperture driving means. A user, therefore, must perform a maintenance operation for, e.g., checking the voltage of a power source battery of the camera main body 10 or replacing the battery before he or she uses the camera, resulting in a very cumbersome operation for the user. Even if the power source capacity of the camera main body 10 is increased, not only must this maintenance operation still be performed, but also the size of the cameral main body 10 is increased by the increase in voltage capacity.
Moreover, the write speed (or time) of the IC memory device in the memory cartridge 12 largely changes in accordance with the type of device. Therefore, as the memory capacity is increased, the difference between write times is increased.
If data transfer is not performed at a proper speed corresponding to the write speed, data writing may fail and data may be lost.
In order to spread the use of the solid-state camera and the solid-state memory apparatus as described above, the size, connecting pins, and the like of the solid-state memory apparatus such as the memory cartridge 12 must be standardized.
If, however, techniques for realizing a large capacity, a high speed, and low power consumption of the IC memory device of the memory cartridge 12 rapidly progress, standardization of the size may prevent use of advanced circuit devices.